Actually, you mean Lumpy (even worse than Itchy as a name!). Itchy was Chewie's father.
I've always kind of considered this fact to be loosely part of the Star Wars world, probably because I saw the Holiday Special when it aired, it was live action, and it was very shortly after Star Wars. Maybe it didn't happen exactly like it was shown in the Holiday Special (let's hope not), but I'll accept that Chewbacca had a family with a son nicknamed "Lumpy".
--SKot